All these are arbitrary. The genetic distance between a European with a high percentage of neanderthal DNA and that of some African populations is probably more comparable than some might expect. And whether we should consider Neanderthals a separate species, is again, probably more debatable than some might expect.
What makes a "race" is basically just total nonsense. Arguably there should be many "races" in Africa given the genetic diversity.
> We all are the same species, but we also all are mixed races.
We're also all mixed-species.